Ventilation vent cap

ABSTRACT

A ventilation vent cap includes a cylindrical main body fitted into a duct placed in the exterior wall of a building so as to communicate between an interior and an exterior; a shielding portion disposed in the exterior via a support member attached to an outdoor-side end surface of the cylindrical main body; and a cover portion blocking vertically an upper part of an air passage extending between the outdoor-side end surface and the shielding portion. The shielding portion is in the shape of a cone whose apex is located in the air passage and above an opening upper end of the cylindrical main body.

TECHNICAL FIELD

The present invention relates to a ventilation vent cap.

BACKGROUND ART

A conventional ventilation vent cap includes a shielding plate on theexterior side to protect from wind and rain (see, for example, PatentLiterature 1). FIG. 8 is a sectional view of a configuration of aconventional ventilation vent cap disclosed in Patent Literature 1.

As shown in FIG. 8, the ventilation vent cap includes cylindrical mainbody 102 placed in duct 101, conical shielding portion 104 fixed tocylindrical main body 102 via support member 103, and cover portion 105covering cylindrical main body 102 and shielding portion 104.

In such a conventional ventilation vent cap, its upper part is coveredby cover portion 105, causing exhaust stream 106 to collide withshielding portion 104 and flow downward. The shape of cover portion 105and shielding portion 104 can cause exhaust stream 106 to have a highpressure loss, and the ventilator to have a low performance.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Unexamined Publication No2009-222270

SUMMARY OF THE INVENTION

The ventilation vent cap of the present invention includes a cylindricalmain body fitted into a duct placed in the exterior wall of a buildingso as to communicate between an interior and an exterior; a shieldingportion disposed in the exterior via a support member attached to anoutdoor-side end surface of the cylindrical main body; and a coverportion blocking vertically an upper part of an air passage extendingbetween the outdoor-side end surface and the shielding portion. Theshielding portion is in the shape of a cone whose apex is located in theair passage and above an opening upper end of the cylindrical main body.

This configuration prevents the exhaust stream from flowing toward thecover portion and then turning into a turbulent flow near the coverportion. This prevents an increase in the pressure loss and a decreasein the performance of the ventilator.

BRIEF DESCIPTION OF DRAWINGS

FIG. 1 is a cross sectional view of a ventilation vent cap according toa first exemplary embodiment of the present invention, and an exhauststream.

FIG. 2 is a perspective view of the ventilation vent cap according tothe first exemplary embodiment and the exhaust stream.

FIG. 3 is a front view where the ventilation vent cap according to thefirst exemplary embodiment is installed.

FIG. 4 is a cross sectional view of a ventilation vent cap according toa second exemplary embodiment of the present invention, and an exhauststream.

FIG. 5 is a perspective view of the ventilation vent cap according tothe second exemplary embodiment and the exhaust stream.

FIG. 6 is a cross sectional view of a ventilation vent cap according toa third exemplary embodiment of the present invention, and an exhauststream.

FIG. 7 is a cross sectional view of a ventilation vent cap according toa fourth exemplary embodiment of the present invention, and an exhauststream.

FIG. 8 is a sectional view of a configuration of a conventionalventilation vent cap.

DESCRIPTION OF EMBODIMENTS

Exemplary embodiments of the present invention will be described asfollows with reference to the drawings.

First Exemplary Embodiment

FIG. 1 is a cross sectional view of a ventilation vent cap according toa first exemplary embodiment of the present invention, and an exhauststream. FIG. 2 is a perspective view of the ventilation vent cap and theexhaust stream. As shown in FIGS. 1 and 2, ventilation vent cap 18includes cylindrical main body 5, shielding portion 8, and cover portion10. Shielding portion 8 is cone 14 having circular bottom surface 8 a.Cone 14 has apex 13 which is located in air passage 9 and is aboveopening upper end 5 a of cylindrical main body 5. Main cylindrical body5 is fitted into duct 4, which is placed in exterior wall 1 of abuilding so as to communicate between interior 2 and exterior 3.Shielding portion 8 is disposed in exterior 3 via support member 7,which is on outdoor-side end surface 6 of cylindrical main body 5. Airpassage 9 is a space between outdoor-side end surface 6 and shieldingportion 8. Cover portion 10 blocks vertically upper part of air passage9 (the upper part in FIG. 1). As shown in FIG. 2, a line connecting apex13 with lower end 11 of circular bottom surface 8 a and a lineconnecting lower end 11 with upper end 12 of circular bottom surface 8 aform an angle θ.

When ventilation is started with the above-described ventilation ventcap, exhaust stream 17 passes through cylindrical main body 5 and thenflows along the surface of cone 14 of shielding portion 8. Apex 13 ofcone 14 is located above opening upper end 5 a of cylindrical main body5, so that exhaust stream 17 can be prevented from flowing toward coverportion 10 and then turning into turbulent flow in the vicinity of coverportion 10. Thus, exhaust stream 17 passed through cylindrical main body5 is smoothly discharged along the surface of cone 14 of shieldingportion 8. This maintains the low pressure loss and high performance ofthe ventilator.

As shown in FIG. 2, exhaust stream 17 leaves air passage 9 through lowerend 11 of circular bottom surface 8 a substantially at an angle of θwith respect to exterior wall surface 1 a. This prevents exhaust stream17 from colliding with exterior wall surface 1 a, so that exterior wallsurface 1 a can be kept clean.

Cover portion 10 is placed in air passage 9. More specifically, coverportion 10 is placed on the upper side of ventilation vent cap 18, thatis, on the ceiling 19 side under the eaves shown in FIG. 3, which is afront view where the ventilation vent cap according to the firstexemplary embodiment is installed. Thus, even if ventilation vent cap 18is installed near ceiling 19, cover portion 10 placed over air passage 9as shown in FIG. 2 prevents exhaust stream 17 from flowing upward andsoiling ceiling 19.

Second Exemplary Embodiment

In a second exemplary embodiment of the present invention, the samecomponents as in the first exemplary embodiment are denoted by the samereference numerals, and the description thereof is omitted. Thefollowing description will be focused on the difference between thefirst and second exemplary embodiments. The second exemplary embodimentdiffers from the first exemplary embodiment in the shapes of shieldingportion 8 and cover portion 10.

FIG. 4 is a cross sectional view of a ventilation vent cap according tothe second exemplary embodiment, and an exhaust stream. FIG. 5 is aperspective view of the ventilation vent cap and the exhaust stream. Asshown in FIG. 4, shielding portion 8 is in the shape of cone 23 whoseapex 13 faces cylindrical main body 5. The base angle of cone 23 is δ.As shown in FIG. 5, cover portion 10 has cover rim on anoutdoor-side-end-surface side 16 on the outdoor-side end surface 6 side,cover rim on the outdoor-side-end-surface side 16 being longer thancover rim on a circular-bottom-surface side 15 on the circular bottomsurface 8 a side of shielding portion 8. Thus, cover portion 10 has endside 26, which extends obliquely downward from circular bottom surface 8a to outdoor-side end surface 6.

When ventilation is started with the above-described ventilation ventcap, as shown in FIG. 4, exhaust stream 24 passes through the lower partof cylindrical main body 5 and then flows along the surface of cone 23of shielding portion 8.

On the other hand, as shown in FIG. 5, exhaust stream 25 passes throughthe upper part of cylindrical main body 5, and flows along cover rim onthe circular-bottom-surface side 15 on the circular bottom surface 8 aside of cover portion 10, then passes through a substantially V shapedregion S formed by the region of cover portion 10 that is in thevicinity of end side 26 and shielding portion 8, thereby beingdischarged to exterior 3 from under end side 26.

At this moment, as shown in FIG. 5, exhaust stream 25 flowing alongcover portion 10 is discharged to exterior 3 from the vicinity of anapex T of the region S on the shielding-portion 8 side. Exhaust stream24, on the other hand, is discharged to exterior 3 smoothly from underend side 26. This prevents an increase in the pressure loss and adecrease in the performance of the ventilator.

It is desirable that the angle δ is in the range of 30° to 70°.

Third Exemplary Embodiment

In a third exemplary embodiment of the present invention, the samecomponents as in the second exemplary embodiment are denoted by the samereference numerals, and the description thereof is omitted. Thefollowing description will be focused on the difference between thesecond and third exemplary embodiments. The third exemplary embodimentdiffers from the second exemplary embodiment in the shape of theshielding portion.

FIG. 6 is a cross sectional view of a ventilation vent cap according tothe third exemplary embodiment and an exhaust stream. As shown in FIG.6, shielding portion 38, which has circular bottom surface 38 a, iscomposed of cones 33 and 34 having different base angles 33 a and 34 a,respectively, instead of being in the shape of a cone. Shielding portion38 projects into air passage 9. More specifically, shielding portion 38is a combination of cone 33 having base angle 33 a and cone 34 havingbase angle 34 a. Base angle 34 a is smaller than base angle 33 a. Theuse of shielding portion 38 having such a shape allows exhaust streams24 and 25 to flow more smoothly along cones 33 and 34, therebypreventing an increase in the pressure loss and a decrease in theperformance of the ventilator.

Base angle 33 a is preferred to be large so that exhaust streams 24 and25 can be prevented from flowing toward exterior wall 1, but large baseangle 33 a requires shielding portion 38 to have a large thickness B.The large thickness B causes shielding portion 38 to block opening 21 ofcylindrical main body 5, making it necessary to increase a distance Cbetween exterior wall surface 1 a and circular bottom surface 38 a.

In the present third exemplary embodiment, shielding portion 38 iscomposed of two cones 33 and 34, and base angle 34 a of cone 34 issmaller than base angle 33 a of cone 33. This allows exhaust streams 24and 25 to flow along cones 33 and 34, while shielding portion 38 can beas thin as possible.

Exhaust streams 24 and 25 flow as follows. As approaching cone 34,exhaust streams 24 and 25 flow radially outward along the surface ofcone 34. When reaching cone 33, exhaust streams 24 and 25 flow alongcone 33, and leave ventilation vent cap 18 at lower end 11, therebybeing discharged to exterior 3. Exhaust streams 24 and 25 never flowtoward exterior wall 1 because they have components in the direction ofbase angle 33 a with respect to exterior wall surface 1 a at lower end11.

Ventilation vent cap 18 has a lower pressure loss (a larger amount ofventilation) with increasing distance between center 20 of shieldingportion 38 and outdoor-side end surface 6. As lower end 11 has a largerangle (base angle 33 a), exhaust streams 24 and 25 are more apart fromexterior wall surface la, making exterior wall 1 more soil resistant (itis desirable that the maximum angle of lower end 11 is 70°). Thus,shielding portion 38 is composed of cones 33 and 34, allowing anappropriate distance between center 20 and outdoor-side end surface 6,thereby reducing an increase in the amount of ventilation and increasingthe angle of lower end 11. As a result, exterior wall 1 can be more soilresistant, and the projection allowance C can be smaller, makingventilation vent cap 18 slim and aesthetically designed. Shieldingportion 38 is composed of two cones 33 and 34 in the present thirdexemplary embodiment, but may alternatively be composed of three or morecones.

Fourth Exemplary Embodiment

In a fourth exemplary embodiment of the present invention, the samecomponents as in the second exemplary embodiment are denoted by the samereference numerals, and the description thereof is omitted. Thefollowing description will be focused on the difference between thesecond and fourth exemplary embodiments. The fourth exemplary embodimentdiffers from the second exemplary embodiment in the shape of theshielding portion.

FIG. 7 is a cross sectional view of a ventilation vent cap according tothe fourth exemplary embodiment, and an exhaust stream. As shown in FIG.7, shielding portion 48 is composed of spherical surfaces 42 and 43having different radiuses, instead of being in the shape of a cone.Shielding portion 48 projects into air passage 9.

Shielding portion 48, which is composed of two spherical surfaces 42 and43, can smoothly change the direction of exhaust streams 24 and 25 thathave passed through the interior from a straight-ahead direction J to ablow-off direction G. This reduces an increase in the amount ofventilation. At lower end 11 where exhaust stream 24 leaves ventilationvent cap 18, exhaust stream 24 flows toward exterior 3 at an anglesubstantially orthogonal to exterior wall 1 without soiling exteriorwall 1. The surface of shielding portion 48 is composed of two sphericalsurfaces 42 and 43 smoothly connected to each other without ridges. As aresult, no problems occur such as dust accumulation in the ridges, sothat the surface of shielding portion 48, and hence the appearance ofthe product itself can be kept clean.

INDUSTRIAL APPLICABILITY

The ventilation vent cap according to the present invention is usefulas, for example, an outdoor hood mounted on the exterior wall of abuilding.

REFERENCE MARKS IN THE DRAWINGS

-   1 exterior wall-   1 a exterior wall surface-   2 interior-   3 exterior-   4 duct-   5 cylindrical main body-   5 a opening upper end-   6 outdoor-side end surface-   7 support member-   8, 38, 48 shielding portion-   8 a, 38 a circular bottom surface-   9 air passage-   10 cover portion-   11 lower end-   13 apex-   14 cone-   15 cover rim on the circular-bottom-surface side-   16 cover rim on the outdoor-side-end-surface side-   17, 24, 25 exhaust stream-   18 ventilation vent cap-   19 ceiling-   20 center-   21 opening-   23, 33, 34 cone-   26 edge-   33 a, 34 a base angle-   25 42, 43 spherical surface

1. A ventilation vent cap comprising: a cylindrical main body fittedinto a duct placed in an exterior wall of a building so as tocommunicate between an interior and an exterior; a shielding portiondisposed in the exterior via a support member attached to anoutdoor-side end surface of the cylindrical main body; and a coverportion blocking vertically an upper part of an air passage extendingbetween the outdoor-side end surface and the shielding portion, whereinthe shielding portion is in a shape of a cone whose apex is located inthe air passage and above an opening upper end of the cylindrical mainbody.
 2. A ventilation vent cap comprising: a cylindrical main bodyfitted into a duct placed in an exterior wall of a building so as tocommunicate between an interior and an exterior; a shielding portiondisposed in the exterior via a support member attached to anoutdoor-side end surface of the cylindrical main body, the shieldingportion being in a shape of a cone whose apex faces the cylindrical mainbody; and a cover portion blocking vertically an upper part of an airpassage extending between the outdoor-side end surface and the shieldingportion, wherein the cover portion has a cover rim on anoutdoor-side-end-surface side, the cover rim being longer than a coverrim on a circular-bottom surface side of the shielding portion.
 3. Theventilation vent cap of claim 2, wherein instead of being in the shapeof a cone, the shielding portion is composed of a plurality of coneshaving different base angles and projects into the air passage.
 4. Theventilation vent cap of claim 2, wherein instead of being in the shapeof a cone, the shielding portion is composed of a plurality of sphericalsurfaces having different radiuses, and projects into the air passage.